Neurostimulators and cochlear implants are fast growing sectors in the medical industry. For example, neurostimulators have been found to be effective in treating epilepsy, chronic pain, depression, and Parkinson's disease. In addition, implantable neural prostheses also present a great potential in improving the condition of those with physical disabilities. However, many of these medical electronic implants and others (e.g., retinal implants and gastric pacemakers) must use batteries, which require periodic replacement. As a result, batteries are often implanted in the chest area. This may require running long electrical lines through the moving parts of the body, such as the neck, to power the stimulators in the head, for example, or other parts of the body, and cause additional reliability issues.
Using an implantable power generator for medical electronics could provide an effective solution to the aforementioned challenges. However, harvestable energy sources are rare inside the human cranial cavity: there are few photons, and microscale thermal gradients are too small for practical power generation. Similarly, harvesting energy from sound waves has resulted in an insignificant power level because air is a very thin medium and highly ineffective for the propagation of mechanical energy. Ambient mechanical vibrations exist, yet previously studied vibration-driven energy-harvesting approaches suffered from irregular availability and widely varying amplitudes and frequencies of ambient vibrations present in biological environments, which made the resonance-based harvesters inefficient and impractical.
Accordingly, there is a present need for systems, devices, and/or methods for efficiently generating electrical power for use in medical electronic implants and/or wearable electronics.